Abstract

High energy resolution X-ray spectroscopy has emerged as a powerful tool for probing the electronic structure and chemical environment of matter with exceptional precision. Techniques such as High Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy (HERFD-XAS), X-ray Emission Spectroscopy (XES), and Resonant Inelastic X-ray Scattering (RIXS) benefit significantly from enhanced spectral resolution, enabling them to disentangle electronic transitions and the resolve subtle spectral features otherwise obscured by the intrinsic broadening of conventional XAS. By employing crystal analyzer optics, these high-resolution methods offer critical insights into electronic and structural properties including oxidation states, ligand-field effects, spin states, and site symmetries.

This talk will introduce the fundamental principles underlying high energy resolution X-ray spectroscopies, with a focus on instrumentation and data interpretation. Applications in catalysis, energy materials, biology and environmental chemistry will be presented to demonstrate how HR-XAS enables the detailed characterization of complex systems under realistic, often dynamic, conditions—including in situ and operando environments.